| Abstract Scope |
This presentation includes my early discussions with Professor Bill Gerberich on the fracture and deformation of quasicrystals when Bill was visiting ETH Zurich and I was a PhD student there in 2014. Quasicrystals, sometimes, can be regarded as an intermediate state between regular metals and metallic glasses, in terms of structural and chemical complexity. A long-standing problem, however, significantly impedes practical usage of quasicrystals: at low and intermediate temperatures, they are very brittle, suffer from low ductility and formability and, consequently, their deformation mechanisms are still not clear. Here, this presentation systematically studies the deformation behavior of icosahedral Al-Pd-Mn and decagonal Al-Ni-Co quasicrystals using a micro-thermomechanical technique over a range of temperatures (25-500 °C), strain rates, and sample sizes, accompanied by microstructural analysis. Here I show interesting phenomena relevant to small-length scales, including cracking, serrated flows, diffusion and phase transformation, as well as the related applications. |